My C320 is smoking!

[John Graham]

Hi guys.
My name is John and I have a 2003 C320 petrol coupe and it's throwing out white smoke like James bond's Aston.
Not using coolant and it smells like oil burning.
I've done the valve seals and cleaned the pcv channel but the problem still remains.
Does anyone have any more ideas I can try?
I await your wisdom.

 

[M80]

Assuming the oil level isn't too high a compression check would be my next move.

 

[LostKiwi]

How's your brake fluid level?

 

[bembo449]

valve seals , as in valve stem seals ??

 

[John Graham]

valve seals , as in valve stem seals ??

Valve stem seals is correct.
I haven't checked brake fluid though.
I didn't even think of that LostKiwi.
I assume you're thinking brake booster's leaking into the intake?

 

[umblecumbuz]

One of the more usual causes of white smoke from a petrol engine - after it has warmed up and no longer puts out 'steam' from a cold exhaust - is an internal coolant leak.
It does not need a massive coolant loss to make a lot of white smoke, so keep checking coolant levels carefully.

Is there a slight sweet smell near the exhaust?
Is the oil level constant, or even rising?
Does the oil look at all frothy?
Is there any oily residue in the expansion tank?

Any or all of these would point to an internal coolant leak - more than likely a leaking head gasket, or even a warped head..

 

[bembo449]

Valve stem seals is correct.
I haven't checked brake fluid though.
I didn't even think of that LostKiwi.
I assume you're thinking brake booster's leaking into the intake?

oh right , guess its one good thing to cross off the list but I feel that someone on here will almost certainly be able to diagnose this issue

 

[LostKiwi]

Valve stem seals is correct.
I haven't checked brake fluid though.
I didn't even think of that LostKiwi.
I assume you're thinking brake booster's leaking into the intake?

Yep. Just remembered I had a faulty seal in a servo years ago and that made lovely clouds of white smoke as it burnt the brake fluid.

 

[John Graham]

oh right , guess its one good thing to cross off the list but I feel that someone on here will almost certainly be able to diagnose this issue

I hope so bembo449 I'm loving the car but the wife thinks it's totalled

 

[John Graham]

Good thinking LostKiwi.
I never would've thought of that.
I'll be checking the fluid as soon as I get home.
Many thanks

 

[John Graham]

Dammit brake fluid is fine.
Time for plan b or c

 

[Uncle Benz]

There is a very narrow oil drain path behind a plate that incorporates the crankshaft rear main oil seal. I have seen this narrow bit blocked with crud before, and it leads to a large back up of oil in the offside cam box. This then finds its way in and causes smoke. I have a picture of the thing somewhere...

 

[Uncle Benz]

You won't believe how far back I had to look to find this picture!

The drain is to the right of the crank. It has almost a U bend in there

 

[John Graham]

You won't believe how far back I had to look to find this picture!

The drain is to the right of the crank. It has almost a U bend in there

That's brilliant information.
Also a ****** stupid design.
I really appreciate finding this for me.
I guess I'm getting out the jack this weekend.

 

[Uncle Benz]

It looks like a silly design, but problems with it are rare. I think I've only seen this twice, three times at the most. Compare that to the number of these I've worked on over the years that have never been affected. It's thousands, literally!

I hate to say it, but it'll be caused by lack of regular oil changes, or using poor quality oil.

 

[John Graham]

It looks like a silly design, but problems with it are rare. I think I've only seen this twice, three times at the most. Compare that to the number of these I've worked on over the years that have never been affected. It's thousands, literally!

I hate to say it, but it'll be caused by lack of regular oil changes, or using poor quality oil.

I'm with you there.
I am a regular oil changer because I don't cover many miles on average.
I gave it an oil change as soon I bought it about 6 months ago and it still looks clean.
Do you think it's worth doing the old "flush with diesel" trick before I dismantle the car?

 

[Uncle Benz]

I'm with you there.
I am a regular oil changer because I don't cover many miles on average.
I gave it an oil change as soon I bought it about 6 months ago and it still looks clean.
Do you think it's worth doing the old "flush with diesel" trick before I dismantle the car?

No, I don't think that's a good idea at all! In my experience flushes tend to dislodge stuff that then blocks the oil pump pick up gauze.

 

[John Graham]

No, I don't think that's a good idea at all! In my experience flushes tend to dislodge stuff that then blocks the oil pump pick up gauze.

Fair enough. I'll bow to your experience.
Thanks again for your advice and I'll get to removing the gearbox at the weekend weather permitting.